Unless otherwise indicated herein, the materials described in this section are not prior art to the claims of this application and are not admitted to be prior art by inclusion in this section.
Solid-state disks based on semi-conductor material may be gradually replacing traditional magnetic spinning disks in desktop computers and servers. In some cases, a solid-state disk may use a flash translation layer (“FTL”) to emulate a block memory device that may be similar to a traditional magnetic hard disk, thus shielding the hardware characteristics of the non-volatile memory used by the solid-state disk. The FTL might be used by operating systems, database systems, and the like to interact with the solid-state disks or other devices.
One function the FTL might perform is cache management for a solid-state disk. For example, the FTL may be configured to cache hot data blocks in a cache of the solid-state disk using a cache management mechanism. Many different cache management mechanisms might be used by a solid-state disk. Generally, these different cache management mechanisms might increase a cache hit rate, reduce the latency of read/write response, and prolong the life of the non-volatile memory used by the solid-state disk. For example, a cache replacement mechanism may determine what data to maintain in a cache and what data to replace in a cache. Some example cache replacement mechanisms that may be used in solid-state disks might be based on the traditional least recently used (“LRU’) cache replacement algorithm, on a variant of LRU, on low inter-reference recency sets (“LIRS’), on a variant of LIRS, or some other cache replacement mechanism. In some cases, however, these cache replacement mechanisms might not perform adequately. Attempting to improve the cache hit rate in order to increase the performance of solid-state disks can be challenging.